How to setup deals with partners?

[Anne *]

I need some help with structuring a partner deal.

Just for background, we've done around 10 real estate deals, but all with our own money/credit.

We found a potential deal, and we're at the point where we're our cash is tied up. So, we might need a money partner.

Three possible scenarios:
1) Partner provides cash (downpayment, fixup) and credit
2) Partner provides cash, we provide credit
3) We split cash requirements 50/50, we provide credit

What's the most fair way to split the profits in these scenarios?

Should we setup a new LLC with the partner (LLC formation cheap in our state)? Or do we writeup a JV agreement? Should we really have a lawyer do this?

Or is there a better way to do this?

Thanks in advance for your help and suggestions!